Likely doesnt change his trade value but Id be damn leery now. Serial behavior of this this kind is a pretty big red flag. I say this assuming there arent criminal charges. Obviously that would change a lot of things.
I would say this changes his trade value significantly, at least for now, unless what is described in every one of these lawsuits is revealed to be fabricated.
The NFL has suspended players for conduct before without criminal charges being involved, and depending on what the league's investigation reveals I would imagine Watson will be missing some games this season. With all this, it probably makes a lot more sense for the Texans to hold on to him for 2021.